Photosynthesis and Photosynthesis and RespirationRespiration

What is photosynthesis?What is photosynthesis?

• A chemical reaction that occurs in plants A chemical reaction that occurs in plants that changes light energy to chemical that changes light energy to chemical energyenergy

• Energy is stored as sugarEnergy is stored as sugar

• Occurs in plants and some algaeOccurs in plants and some algae

• Takes place in chloroplasts in Takes place in chloroplasts in chlorophyllchlorophyll

What happens during photosynthesis?What happens during photosynthesis?

• Plants capture light energy and use it to Plants capture light energy and use it to make glucosemake glucose

• Sunlight provides the energy to change Sunlight provides the energy to change molecules of carbon dioxide and water into molecules of carbon dioxide and water into glucoseglucose

• Oxygen is a byproduct and is released during Oxygen is a byproduct and is released during this processthis process

The photosynthesis recipeThe photosynthesis recipe

Carbon Dioxide + waterCarbon Dioxide + water Glucose + oxygenGlucose + oxygen REACTANTSREACTANTS PRODUCTSPRODUCTS

LIGHT ENERGYLIGHT ENERGY

The equation of the chemical reaction The equation of the chemical reaction photosynthesisphotosynthesis

6 CO6 CO22 + 6 H + 6 H22OO CC66HH1212OO66 + 6O + 6O22

REACTANTSREACTANTS PRODUCTSPRODUCTS

LIGHT ENERGYLIGHT ENERGY

Why is this important to us?Why is this important to us?

• We cannot make our own food, and depend on We cannot make our own food, and depend on producers such as plants to provide glucose and producers such as plants to provide glucose and energyenergy

• Plants are the first part of food chains, and an Plants are the first part of food chains, and an integral (important) part of food websintegral (important) part of food webs

• Without producers, consumers would not be able Without producers, consumers would not be able to get energy, and would most likely dieto get energy, and would most likely die

What about the oxygen released?What about the oxygen released?

• This becomes part This becomes part of the air that we of the air that we breathe, and is breathe, and is necessary for all necessary for all living thingsliving things

From the producer to the consumer…From the producer to the consumer…

• Once the energy from the sunlight is Once the energy from the sunlight is converted into chemical energy by converted into chemical energy by photosynthesis, an organism has to transfer photosynthesis, an organism has to transfer that energy into a usable form, called ATPthat energy into a usable form, called ATP

• Transferring the energy into a usable form is Transferring the energy into a usable form is called cellular respirationcalled cellular respiration

Cellular RespirationCellular Respiration

• Takes place in the cells and mitochondria of Takes place in the cells and mitochondria of all living thingsall living things

• That means Animals That means Animals ANDAND Plants Plants

• Is a step by step process that breaks down Is a step by step process that breaks down glucose molecules to release energyglucose molecules to release energy

The recipe for cellular respirationThe recipe for cellular respiration

Glucose + oxygen Glucose + oxygen Carbon Dioxide + waterCarbon Dioxide + water + + ENERGYENERGY

REACTANTSREACTANTS PRODUCTSPRODUCTS

The chemical equation for cellular respiration is

CC66HH1212OO66 + 6O + 6O2 2 6 CO6 CO22 + 6 H + 6 H22OO

+ + ENERGYENERGY

REACTANTSREACTANTS PRODUCTSPRODUCTS

Aerobic Respiration

• Organisms that use Oxygen to free the energy from their food are said to use Aerobic Respiration

• Aerobic means “using oxygen”

Anaerobic Respiration

• Organisms that do not use oxygen but have developed another way to release the energy from their food are said to use Anaerobic Respiration.

• Remember that the prefix A- or An- means NOT so Anaerobic means “not aerobic” or without oxygen.